1. Field of the Invention
This invention is directed to a respiratory monitor monitoring the respiration rate of a person and/or an excessive intrathoracic or abdominal pressure monitor and more particularly to a respiratory and pressure monitor which is not affected when the person using it rolls over. The device of the present invention is especially useful for the early detection of Sudden Infant Death Syndrome, thereby allowing time for action to be taken to prevent the death of an infant.
2. Description of the Prior Art
Sudden Infant Death Syndrome is the sudden and inexplicable death of an infant as a result of respiratory failure. Evidence has shown that at the onset of Sudden Infant Death Syndrome, there is an intense struggle by the infant to survive. High intrathroacic pressures appear to be involved. These pressures are substantially higher than those associated with a normal cough as is found in common colds. Also associated with Sudden Infant Death Syndrome is a cessation of respiration which ultimately results in death. Devices which monitor both respiration and excessive intrathoracic or abdominal pressure to provide an indication of the onset of Sudden Infant Death Syndrome have not been found in the prior art.
Prior art respiratory monitors are strapped to an individuals chest are known in the art. Two examples of these prior art devices are dislcosed in U.S. Pat. Nos. 3,097,639 and 3,268,845. Both of these prior art devices have a strap or band which fits around a persons chest and a variable resistance device connected between the ends of the strap. When the persons chest expands, the resistance of the resistance device is altered. This change in resistance is detected and is used to provide an indication of the individuals respiration rate.
Still another type of prior art respiration monitoring device is shown in U.S. Pat. No. 3,782,368 which discloses a piezoelectric device which is attached to a band or strap which is placed around a persons chest.
All of these prior art devices, however, have the disadvantage that the person whose respiration is being monitored must lie on their back or side when the detecting device is mounted on their chest. If the person rolls over under their chest, then the persons weight will be on the respiration detector and affect its operation. Certainly when a person is sleeping there is always the possibiity that he will roll over onto his chest and thus the effectiveness of the device, at its most critical time, that is when a person is sleeping, is greatly reduced. The lying of person on his chest would also affect the detection of intrathoracic or abdominal pressure.